Ground-based detection technology of South Pole Telescope is the first to “check up” on ice snow track of Winter Olympics

2022-07-17 0 By

As the “pearl in the crown of the Winter Olympic Games”, alpine skiing is a comprehensive competition of technology, courage, speed and physical quality.Since the opening of the Beijing Winter Olympic Games, the National Alpine Skiing Center, known as “snow flying Swallow”, has helped athletes achieve great achievements in sports and won praise from all walks of life.In the men’s downhill alpine skiing, Norway’s Seyerstede set the fastest speed of the race, reaching a speed of 139.71 kilometers per hour.How to help the athletes to glide at high speed and safely, and how to ensure the fairness of the competition, so that the snowquality of the track before and after the start of the skiers is consistent, which has high requirements for the construction of the track.Since 2020, national astronomical observatory, Chinese Academy of Sciences institute of nanjing astronomical optical technology (hereinafter referred to as “nanjing sky) and the Chinese academy of meteorological sciences research team constantly overcome difficult, independent research and development” particle size detector “and” ice intensity detector “, for the ice snow “check-up” track, the efforts of high-speed taxi for athletes, reduce sports injuries to provide technical support.”It’s worth it to watch the athletes keep making great achievements.”Hakun Wen, associate researcher of Nanjing Tianguang Institute, is both proud and pleased to realize the same dream in the same stadium.It is worth noting that the key technology of these detection equipment was derived from the ground-based detection of Chinese telescopes in the Antarctic Dome A region.These technologies were the first to be proven at the Winter Olympics.Haekun Wen (right) and her research team measure the hardness of the ice snow track in Zhangjiakou Yunding Ski Park. The particle size tester and snow and ice strength tester help the track meet the standards. “The ice snow track is used in alpine skiing competitions, which can be described as the ‘expressway’ of the ski track.”Wen told Science and Technology Daily that unlike natural snow, icy snow has a thin hard ice shell on its surface, which reduces the friction of the track surface on the skis.The ice snow track is divided into competition and speed racing. The competition track has high requirements, and the snow density is generally about 600-700 kg/m3, while the speed track is about 550-600 kg/m3.After the track is laid, whether it can meet the needs of the race requires particle size detectors and snow and ice strength detectors to “check up”.”The near-infrared laser in the particle size detector will be irregularly reflected in all directions as it passes through the rough surface of the piste, causing the laser intensity to be weakened.The intensity of laser attenuation is related to the roughness of the ski surface, which is determined by the size of the icy snow.”Wen explained that particle size is a measure of the strength of icy snow. The smaller the particle size is, the closer the molecular arrangement is, and the stronger the trail is. Generally speaking, millimeter particle size is ideal.The laser can determine whether the size of the icy snow meets the requirements of the event.Snow and ice intensity detection is another important indicator to reflect the quality of the track.”If the piste is hard, the piste will be in a relatively perfect condition no matter which runners start, ensuring the fairness of the competition.The track should have features similar to a plastic track, with grip and flexibility to ensure that the athlete does not get injured when sliding or jumping.”According to Wen, the ice and snow strength tester drives a probe into the ice and snow track and uses a cryogenic sensor to read the reaction force of the probe to determine the hardness of the track at different depths.Over the past year, team members have been to Beijing Yanqing, the host city of the Winter Olympic Games, Zhangjiakou in Hebei province, and Yabuli Winter Sports Training Base in Harbin, Heilongjiang Province for several times to test the ice snow track, and obtained maps of changes in grain size and strength of ice and snow at different depths, helping the track meet the standards.The key technology is based on the ground-based detection of the South Pole Telescope.According to Wen, these technologies were initially prepared for China to build the foundation of A telescope in the Antarctic Dome A region.Dome A, the highest point of the Antarctic ice sheet, is one of the best astronomical observation sites on Earth.China has built a Kunlun station in the region and installed three optical telescopes, which have achieved a number of cutting-edge observation and research achievements.”In the future, China will add a 2.5-meter high resolution optical infrared telescope with a large field of view.In order to get good observations and minimize the impact of airflow, the telescope has to be set up on a 15-meter tower, so the snow base has to be very stable.”In 2017, Wen and his team undertook the National Natural Science Foundation of China (NSFC) “Research on Parametric Design Method of Dome A Telescope Piers”.One big problem for researchers is that although dome A’s ice core is about 4,000 meters thick, Antarctica has A wide range of seasonal temperature differences, with temperatures as low as about minus 80 degrees Celsius in winter and as low as minus 40 degrees Celsius in summer.If the ice floats, the foundation on which the telescope is built will come loose.How to choose stable ice surface is particularly important. In recent years, the Antarctic team of Nanjing Tiangang Institute has been testing and studying the bearing capacity of ice and snow foundation in Kunlun Station area, and the project will be concluded in 2020.However, what Wen did not expect was that with the arrival of the Winter Olympics, the key technologies of the ice and snow particle size detector and ice and snow strength detector were first applied in the Winter Olympics. However, due to the different application environment, the instrument was not developed smoothly at the beginning.”At first we developed the device in the natural snow state, but when we tested it, we found that the snow on icy snow track is denser and harder, and the instrument can’t measure through the track.”Wen and his team adjusted the parameters and finally tested the ice-snow track with different climate conditions and different water injection intensities.”To make icy snow tracks in different weather conditions, water injection intensity and time are different.If the water injection intensity is high, the water flow is fast and the water temperature is high, the upper layer of the ice will become soft;If the water is injected for a long time, the ice will harden.”According to Wen, through testing and analysis, the team has come up with a specific plan to create the best quality ice snow track in different climates to provide support for the event.”In the future, we will continue our research on ice snow track to escort Chinese ice athletes.””Wen said.Editor: Zhang Shuang review: Yue Liang